The urine gamma-glutamyl transferase (GGT)-to-creatinine ratio has been used to monitor patients at risk of acute renal injury. We validated the spectrophotometric quantification of GGT in urine in a commercial biochemistry analyzer.The assay was precise, accurate, and linear. Intra-assay precision was 3.59% in 4 samples, with GGT concentrations of 47-195 U/L. Inter-assay precision in 3 samples with activities of 11-51 U/L was 7.74%. Accuracy was 97.3%, with an absolute bias of 2.7 U/L. Urine GGT was unaffected by hematuria, hemoglobinuria, or bacteriuria. Urine GGT was stable at 20°C and 4°C for up to 3 d. Storage by freezing at −20°C resulted in a significant reduction in enzyme activity. A pH outside the range of 6.5-8 resulted in reduced GGT activity. The biological variation of urine GGT-to-creatinine ratio provided an index of individuality of 1.6, indicating that a population-based reference interval (RI) can be used. The reference change value was calculated, and an increase in consecutive measurements >43% is required to be regarded as significant. The urine GGT-tocreatinine ratio RI obtained in a population of 41 healthy dogs was 8.5-28.5 U/g.

Cell structures morphologically consistent with Blastocystis were aspirated from a subcutaneous facial swelling in a 13-mo-old pet duck. On PCR analysis and sequencing, the organism was confirmed as Blastocystis sp. subtype 7. Blastocystis is a single-celled protist that is found in the intestinal tract of many species, including mammals, birds, reptiles, amphibians, and insects. A complete understanding of the lifecycle and pathogenesis of the parasite remains elusive. Blastocystis has been implicated in human and animal disease; however, its role is controversial given that it is commonly found among healthy gut microbiota. Infection with Blastocystis outside the intestinal tract has been reported only rarely in humans. Our case of subcutaneous Blastocystis infection in a duck is a novel presentation of a ubiquitous, generally asymptomatic, parasite or commensal of the intestinal tract.

An 11-year-old Labrador retriever was evaluated for bilateral ocular discomfort and visual deficits. Ophthalmic examination revealed bilateral uveitis with secondary glaucoma; the right eye was blind. Further investigations revealed bilateral retinal detachment, a diffuse interstitial lung pattern and bilateral focal adrenomegaly. Aqueocentesis of the left eye diagnosed a melanocytic malignancy, whereas only inflammation was detected in the right eye. A staged bilateral enucleation was performed and histopathology revealed metastatic melanoma in both eyes. Complete staging diagnosed an unrelated pulmonary neoplasm but failed to detect a primary site of the melanoma. The patient was euthanased 17 weeks post diagnosis due to development of neurological signs. Postmortem examination confirmed disseminated melanoma but failed to reveal a primary site. This unusual case highlights the diagnostic utility of bilateral aqueocentesis in canine uveitis investigation and the critical role of histopathological evaluation of enucleated globes to discriminate between primary and metastatic neoplasia in the eye.